The present invention relates to an arrangement for a spring suspension system which contains a load-absorbing or a mass-supporting mechanical main spring and a unit consisting of inner and outer cylinders. In such arrangement a piston and/or a piston rod, for the purpose of providing a damping function, works in an incompressible fluid, for example hydraulic oil, inside a working space, and with its corresponding area, via the fluid, works against the effect of a spring function produced by the main spring with the help of a moving device capable of being actuated through its first side by the main spring and capable of being actuated through its second side by the incompressible medium.
The application of maintaining the incompressible fluid during the return stroke of the piston is known in art. In the case of shock absorbers, for example, the arrangement of a gas cushion (gas spring) has been disclosed which is separated from the incompressible fluid with the help of a floating piston, one side of which is acted upon by the fluid, and the other side of which is acted upon by the gas cushion. The compression ensures that no gas is released within the fluid, which in turn provides the necessary conditions for sound function.
Also previously disclosed in relation to spring suspension systems for motor vehicles is the use of a moving device or a device which is capable of longitudinal displacement, the respective sides of which are acted upon by the main spring and by the incompressible medium. The main spring contributes to, or produces the compression of the fluid.